How to block spammers!!!!!!

Dear friends,

I have created forum for my seo website. But Iam getting lots of spamming. How can I Block that Spamming?

Thanks

 

Use CAPTCHAs to stop bots. But there is no way to stop manual SPAMs.

 

Which forum are using , each has defences for example new members should not begin threads until 10 posts you can create user groups to manage this.
you can also check this thread :
http://forums.digitalpoint.com/showthread.php?t=362354

 

It was many spam links a couple of days ago also on dp.
I think the idea with begin threads until 10 post is good , maybe you can add also after 7 days,or can't post live links until they have 50 posts.